Effect of Soothing Noise on Sucking Success of Newborns

Abstract

Background:

Starting and continuing breastfeeding are influenced by many factors affecting the mother and the infant. No study is found in the literature investigating how to achieve success in the first nutrient-sucking experiences by decreasing the stress experienced by newborns during the adaptation phase of the early postpartum period. The objective of this study was to determine the effect of soothing noise on sucking success in full-term infants.

Materials and Methods:

This semi-experimental study was conducted with a total of 127 newborns: 64 in the control group and 63 in the experimental group. The data were collected by the researchers using the Mother and Infant Descriptive Information Form and the LATCH Breastfeeding Assessment Tool, in accordance with the literature. Infants in the experimental group (n=63) were exposed to soothing noise (a song) during the first breastfeeding after birth and again 24 hours later, and their sucking success was assessed. No intervention was applied to the infants in the control group.

Results:

The results demonstrated that the sucking success of newborns who were exposed to soothing noise in the early postpartum period was higher than that of the control group (p<0.05).

Conclusions:

It was revealed that exposure to soothing noise is effective for the development of newborns' sucking behaviors as they adapt to extrauterine life in the early postpartum period.

Introduction

Labor is a quite traumatic experience for the newborn. In this period, the newborn begins to achieve homeostasis physiologically while becoming acquainted with, discovering, and experiencing him- or herself and the outside world. Sucking/breastfeeding is of prime importance among these experiences.¹

Although the breastfeeding support strategies that have been implemented around the world for many years have generally increased breastfeeding rates, these rates still have not reached the desired level in terms of starting breastfeeding immediately, feeding only with breastmilk for the first 6 months, and continuing with the total 2-year period of breastfeeding.^2,3 Starting breastfeeding within the first hour after birth is very important in order to ensure that the mother and the newborn have success during these first experiences. Starting and continuing breastfeeding are influenced by many factors affecting the mother and the infant. Large numbers of studies have been conducted on various methods, such as education, consultation, and evidence-based practices, which aim to bring under control the factors affecting the mother while starting and continuing breastfeeding.^4–6 However, no study is found in the literature investigating how to achieve success in the first nutrient-sucking experiences by decreasing the stress experienced by newborns during the adaptation phase of the early postpartum period.

Hearing, which develops during Weeks 20–22 of pregnancy, is an important sensory experience that can create important physiological and behavioral results during the entire lifetime.^7–9 Scientific evidence confirms that the fetus can hear various sounds coming from the mother and from the intrauterine environment and can learn these sounds.^8–10 During intrauterine life, the fetus hears sounds created by the amniotic fluid, sounds from its own movement in the uterus, the sound of blood flowing through the mother's arteries, the mother's heartbeat and gastrointestinal system, and sounds echoing from the outside environment; it grows accustomed to all of these.^8,11 Purposeful sounds such as music can be useful in any phase of newborn care because of the neurologic development potential in terms of teaching and comforting.^12,13 Related studies have indicated that music increases fetal movement.^13,14

Sound that is referred to as “white noise” or “white sound” is a continuous monotone in the form of resonance that suppresses disturbing sounds coming from the outside environment, and it has a soothing effect.¹⁵ The characteristics of white noise are similar to those of the sounds in the mother's womb. It is known that, while in the womb, the infant is affected by the mother's heartbeat and that familiar sounds and rhythms after birth have a soothing effect on the infant.^7,15 There is evidence in the literature confirming that intrauterine sounds have stress-reducing, anxiety-reducing, and soothing effects on fetuses and newborns and that physiological parameters are positively affected.^15,16 From the perspective that the soothing and comforting effect of white noise eases the newborn's adaptation to extrauterine life, this study was conducted with the purpose of specifying the effect of soothing noise on sucking success in newborns.

Materials and Methods

This semi-experimental study was conducted at a maternity hospital in the eastern region of Turkey between April 1, 2013 and February 20, 2014. The population of this study consisted of mother–infant dyads for infants who were born during the study period and met the inclusion criteria. The study was conducted on the whole population without selecting the sample group. This group consisted of 127 mother–infant dyads, who were divided first into the control group (n=63) and then into the experimental group (n=64). In order to calculate the sample size in the end of the study, the Java Applets Power and Sample Size calculation program of Lenth¹⁷ was used. A power analysis was conducted, with 63 individuals included in the control group at a confidence interval of 95%, and the power of the study was found to be 0.90 with a margin of error of 0.05.

The control group was enrolled in the study first, in order to prevent mother–infant dyads in the control and experimental groups from affecting each other. The first 63 mother–infant dyads who met the inclusion criteria were included in the control group; the second 64 mother–infant dyads constituted the experimental group. Though they had accepted to participate in the study in the beginning, the mother of one newborn in the control group and two newborns in the experimental group withdrew from the study, and they were excluded from the analysis.

The inclusion criteria for this study were newborns whose gestational age was between 38 and 42 weeks, whose birth weight was 2,500–4,000 g, and whose Apgar score was 8 or above in measurements at 1 minute and 5 minutes and whose mothers had volunteered to participate in the study. The exclusion criteria for this study were newborns with any anatomical or physiological problems, disease indications, or birth defects, congenital or acquired malformations regarding hearing, and relatives with hearing loss that started in childhood.

Approval of the ethics committee (Ataturk University Faculty of Medicine Non-Pharmacological Clinical Trials Ethics Committee, protocol number 2013/68) and official permissions from the hospital where the study was conducted were obtained. Additionally, informed written consent was obtained from each family included in the study.

Data were collected by the researchers using the face-to-face interview method with the Mother and Infant Descriptive Information Form, the LATCH Breastfeeding Assessment Tool, a music player, a decibel meter, and a soothing-noise CD. However, because the LATCH tool is an observation-based form, it was filled out by the researcher and an observer (the nurse) through observation. Agreement between the independent observers, evaluated by kappa analysis, was found to be almost perfect.¹⁸

Mother and Infant Descriptive Information Form

This form includes descriptive questions regarding the mother and the newborn, prepared by the researchers in line with the literature.^15,16

LATCH Breastfeeding Assessment Tool

The LATCH Breastfeeding Assessment Tool was developed by Jensen et al.¹⁹ in 1994. The LATCH is an assessment tool that was generated by an analogy with the Apgar score system in terms of scoring method. Its evaluation is as fast and easy as the Apgar score.²⁰ The Turkish validity of the LATCH Breastfeeding Assessment Tool was established by Yenal and Okumuş²⁰ in 2003. The LATCH Breastfeeding Assessment Tool is composed of five evaluation criteria. The LATCH acronym is a combination of the English equivalent of the initial letters of these five criteria: L (Latch on breast), how well the infant latches onto the breast; A (Audible swallowing), the amount of audible swallowing noted; T (Type of nipple), the mother's nipple type; C (Comfort breast/nipple), the mother's level of comfort in relation to the nipple; and H (Hold/Help), the amount of help the mother needs to hold her infant to the breast.

Each item is evaluated on a scale between 0 and 2. The lowest (0) and the highest (10) scores can be obtained from the charting system.²⁰ The highest score shows the infant's sucking success. Cronbach's alpha coefficient of the LATCH tool was found to be 0.94 by Demirhan,²¹ 0.96 by Koyun,²² and 0.95 by Yenal and Okumuş.²⁰ For the LATCH tool in this study, Cronbach's alpha coefficient was determined to be 0.84. In this study, the researcher and the observer scored the LATCH tool simultaneously and separately during two different breastfeeding periods, and both assessed each newborn. Before starting the study, the observer was trained by the researchers on using the LATCH Breastfeeding Assessment Tool.

Soothing-noise CD

In the study, newborns were exposed to the song “Don't Let Your Baby Cry—2” from the album “Colic,” released by Orhan Osman of the On Music Production Company. Osman arranged this album using as an example “The Happiest Baby” by Dr. Harvey Karp, which is composed only of intrauterine sounds with the aim of soothing babies. Distinct from that album, Osman also worked on frequencies apart from intrauterine sounds and added sounds such as white noise and music he composed under those frequencies. A music player and a decibel meter were used to deliver the soothing noise; the sound level was adjusted to an average of 55 dB, using previous studies as references.^16,23,24

Procedure

In the begining of this study, the researchers interviewed the mothers and filled in the Mother and Infant Descriptive Information Form, requiring about 5 minutes for each mother. Two breastfeeding sessions by the mothers of the newborns in the control and experimental groups were assessed. It was not said in which breastfeeding period that the observation would be conducted. The breastfeeding sessions of mothers who had vaginal births were examined first after they were taken to the early postpartum unit (within 30 minutes after birth) and again after 24 hours. The breastfeeding sessions of mothers who had had cesarean sections were examined first after arriving at the cesarean service (within 1 hour after birth) and again after 24 hours.

Control group (n=63)

No implementation was performed in this group. No attempts were made by the researcher to support breastfeeding, except for demonstrating the proper position for the mother and the infant during breastfeeding. The LATCH Breastfeeding Assessment Tool was scored by the researcher and the observer during both breastfeeding sessions. The time allowed for breastfeeding was not limited; however, the LATCH assessment was conducted within the first 10 minutes of breastfeeding.

Experimental group (n=64)

Newborns in this group were exposed to soothing noise during breastfeeding. Immediately before breastfeeding, soothing noise was begun at 55 dB through a music player located 1 m from the mother and infant. Sounds in the environment, except for the soothing noise, were controlled. No attempts were made by the researcher to support breastfeeding, except for demonstrating the proper position for the mother and infant during breastfeeding. The soothing noise was continued until the end of the breastfeeding session. The LATCH Breastfeeding Assessment Tool was scored by the researcher and the observer during both breastfeeding sessions. The time for breastfeeding was not limited; however, the LATCH assessment was conducted within the first 10 minutes of breastfeeding.

Statistical analysis

The data obtained from this study were evaluated with computer software. Percentage distribution, mean, chi-squared test, independent-samples t test, analysis of variance, and Cronbach's alpha coefficient calculation, as well as the kappa test for agreement analysis among independent observers, were used to assess the data. The results were assessed at a confidence interval of 95% and with a significance level of p<0.05.

Results

The mean gestational age of the newborns in the control group was 38.86±0.71 weeks, and their mean birth weight was 3,185.98±303.17 g, whereas the mean gestational age of the newborns in the experimental group was 38.71±0.77 weeks, and their mean birth weight was 3,159.13±398.23 g. In addition, 53.1% of newborns in the control group and 55.6% of those in the experimental group were male. It was determined that 50% of newborns in the control group and 52.4% of those in the experimental group were born via vaginal delivery. The gender, delivery method, gestational age, birth weight and height, and 1- and 5-minute Apgar scores of the newborns, as well as the age group and education level of the mothers and their total number of children, were similar in the control and experimental groups (p>0.05) (Table 1).

Table 1.

Comparison of Control and Experimental Groups According to the Mother's and Infant's Descriptive Characteristics

Variable	Control group (n=64)	Experimental group (n=63)	Test	p value
Infant
Gestational age (weeks)^a	38.86 (0.71)	38.71 (0.77)	t=1.104	0.272
Birth weight (g)^a	3,185.98 (303.17)	3,159.13 (398.23)	t=0.428	0.669
Height (cm)^a	48.84 (1.94)	49.12 (1.87)	t=0.858	0.392
Apgar scores^a
1 minute	8.64 (0.65)	8.66 (0.62)	t=0.230	0.818
5 minutes	9.70 (0.58)	9.65 (0.63)	t=0.488	0.627
Gender			χ²=0.076	0.783
Female	30 (46.9)	28 (44.4)
Male	34 (53.1)	35 (55.6)
Delivery method			χ²=0.072	0.788
Vaginal	32 (50.0)	33 (52.4)
Cesarean	32 (50.0)	30 (47.6)
Mother's age group (years)			χ²=1.632	0.442
17–25	26 (40.6)	27 (42.9)
26–34	32 (50.0)	26 (41.3)
≥35	6 (9.4)	10 (15.9)
Mother's education level			χ²=0.829	0.661
Illiterate	11 (17.2)	10 (15.9)
Primary	48 (75.0)	45 (71.4)
High	5 (7.8)	8 (12.7)
Number of children			χ²=1.017	0.602
1	20 (31.3)	18 (28.6)
2	20 (31.2)	25 (39.7)
3 or more	24 (37.5)	20 (31.7)

Data are number (%) unless indicated otherwise.

Mean (SD).

In this study, the mean LATCH scores of the newborns in the experimental group (8.61±1.37), who were exposed to soothing noise, were found to be higher than in the control group (6.52±1.79), with a statistically significant difference (p<0.05) (Table 2).

Table 2.

Comparison of Mean LATCH Scores of Newborns in the Control and Experimental Groups

	Control group (n=64)	Experimental group (n=63)	t value	p value
LATCH	6.52 (1.79)	8.61 (1.37)	7.370	0.000

Data are mean (SD) values.

Discussion

The length of time an infant is breastfed is influenced by factors such as the time of the first breastfeeding, sucking/breastfeeding success, breastfeeding frequency, the starting time of nutritional supplements, and the professional life of the mother.²⁵ The early postpartum period is a critical time for the process of mother–infant attachment, as well as for the mother's ability to breastfeed and for the infant's sucking success.²⁶ The first hours of the life after birth are a stressful period that newborn adapt to the extrauterine life.² This period can be negatively affect to the sucking success of the newborn.²⁷ Sullivan²⁷ reported that intense anxiety experienced by a newborn prevents the infant from feeling safe and decreases his or her sucking/feeding success. Previous studies indicated that the mother's voice, intrauterine sounds, and music decreased the stress of a newborn in the early postpartum period.^28–33

Music is a unique resource that can be used in this process.²⁸ In recent studies, it has been specified that purposeful sounds such as music can be used in any phase of newborn care in order to decrease stress, balance the heart rate and respiration, accelerate growth, and decrease the duration of the hospital stay because these sounds have the potential to teach and comfort and to encourage neurological development.^7,12,13 Standley²⁹ stated that newborns are very sensitive to music therapy techniques after birth. Music-related experiences not only meet the emotional needs of newborns, but also make them feel safe, especially in stressful periods, and help encourage their nutritional intake.²⁸ In another study, it was specified that in the early postpartum period, soothing music supported the breastfeeding/sucking behaviors of the mother and infant.³⁰ Soothing or white noise, known for its similarity to the sounds the baby is exposed to in the womb, plays a role in suppressing disturbing sounds coming from outside, thereby soothing the infant.^8,15

In this study, it was determined that the mean LATCH scores of newborns in the experimental group, who were exposed to soothing noise, were higher compared with those of the control group. When the related literature was examined, no study was found that investigated the effect of soothing noise on the sucking success of newborns. However, there have been studies in the literature in which full-term and preterm newborns' sucking behaviors with and without nutrients were evaluated using intrauterine sounds and soothing music therapy.^13,29,31,34 There are also studies in the literature indicating that if the music played during the last trimester of pregnancy is also played during birth, the fetus perceives the environment as more familiar.^13,14 In studies by DesCasper and Carstens³¹ concerning newborns, they stated that there was a relationship between music and sucking behavior. In a study conducted by Standley¹³ in order to specify the effect of a lullaby sung by a female singer on the sucking behavior of premature infants, it was proven that the amount of nutrients infants took in orally increased and that their sucking activity was strengthened.

In a study conducted by Kawakami et al.,³² newborns under stress were exposed to the sound of the mother's heartbeat or to white noise, and it was determined that the stress indications of the group exposed to white noise were significantly lower compared to the heartbeat group and the control group. In the study of Lee,³³ it was specified that the maternal heartbeat stabilized the behavioral conditions of newborns. In another study, it was determined with electroencephalography that intrauterine sounds stabilized the behavioral conditions of the fetus and the newborn.³⁵ In their study, Kurihara et al.³⁶ indicated that the behavioral stress indications of full-term infants who listened to their mother's heartbeat under stressful conditions, and the steroid hormone levels detected in their saliva, were significantly lower than in the control group. The results of this study were similar to those of the previous studies. The results of the present study showed that soothing noise positively affected the sucking success of newborns, decreasing the stress to which they are exposed.

Conclusions

This study determined that soothing noise has a positive effect on the sucking success of newborns as they adapt to extrauterine life in the early postpartum period. Based on the findings of this study, it is recommended that nurses and midwives who provide care for newborns in the early postpartum period play soothing noise in order to improve the newborns' sucking behaviors. This study was not a randomized controlled study; therefore, future attempts in this area should be conducted in a randomized controlled trial format.

Footnotes

Disclosure Statement

No competing financial interests exist.

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